Germination of Forest Trees 35 
of it that had never been attacked. Some of the questions that 
are immediately called to mind by a mere statement of the prob- 
lem are: Does light affect germination in any way? Does light 
affect the germination of tolerant and intolerant species differ- 
ently? How does soil moisture content affect germination? Do 
drought-enduring species and moisture-loving species behave 
alike in this respect? What is the effect of soil texture upon 
germination? Has the amount of air or oxygen in the soil any 
significance in germination? Since soil texture affects mainly 
the moisture content of the soil, does soil texture affect drought- 
enduring species in the same way as moisture-loving species ? 
The data collected upon the effect of habitat factors on germina- 
tion will be presented in four parts. The effect of light, soil 
moisture, and soil texture will be taken up in the order named 
and following this there will be given a résumé of the relative 
effect of all habitat factors. The three most important points 
to be noted in germination, are the number of days it took until 
germination began, the total number of days in the germination 
period, and the final germination per cent. The rate of germina- 
tion is shown by curves for certain representative species. The 
length of the germination period was taken as the total number 
of days during which any seeds germinated. Records were kept 
long after germination ceased, so that the germination period was 
ended at the time the last seed germinated. To give data as to 
the period of greatest activity involves certain arbitrary standards 
and this method, though tried in compiling the present data, was 
abandoned. The effect of light, soil moisture, and soil texture 
upon the periods of greatest activity is best shown by the curves 
offered for certain representative species. 
The original data was taken by two-day periods. Every other 
day the number of seeds that germinated were counted and re- 
corded. In most cases these were immediately pulled up; but 
where growth measurements were to be taken later the seedlings 
were allowed to grow. 
The first three tables show the effect of light upon the germina- 
tion of eastern species, Rocky Mountain species, and Pacific coast 
species respectively. Three sets of figures are given under each 
